by Kevin McCoy, USA TODAY

by Kevin McCoy, USA TODAY

NEW YORK - Months of trial evidence proves that five former Bernard Madoff employees knowingly participated in and profited from their boss's massive Ponzi scheme, a federal prosecutor argued Tuesday as closing arguments in the fraud trial began.

"Day after day, year after year, these defendants told an avalanche of different lies that allowed Madoff to steal billions from investors," said Assistant U.S. Attorney John Zach, adding that each of the five played a "crucial role" and told a "staggering" number of lies that enabled the investment advisory business fraud to run for decades.

The former co-workers acted out of "greed," argued Zach, who highlighted prosecution evidence showing they collectively received tens of millions of dollars in salaries, bonuses, purported trading profits and other unmerited perks.

Defense lawyers were scheduled to start their closing arguments Wednesday. They have argued that the ex-Madoff staffers were unknowingly hoodwinked by a dishonest and manipulative boss who masterminded a record-setting fraud that bilked as much as $20 billion from thousands of clients worldwide.

The Manhattan federal court conspiracy and securities fraud case is the first criminal proceeding to be considered by a jury because Madoff pleaded guilty without standing trial after the scam collapsed in December 2008. He's now serving a 150-year prison term.

The former co-workers face long prison terms of their own if convicted at the close of the trial that began in October. They are: Daniel Bonventre, 67, Madoff's former operations manager; Annette Bongiorno, 65, the longtime employee who allegedly helped manage the bogus trading operation; JoAnn Crupi, 52, who had day-to-day oversight of the business' bank account; and ex-Madoff computer programmers Jerome O'Hara, 50, and George Perez, 48.

Zach outlined details of government evidence against each of the five as he began a closing statement scheduled to conclude Wednesday.

Bonventre "cooked the books of Madoff Securities for decades," keeping the bank account of the Manhattan-based business' investment advisory division hidden off the general ledger and concealing the truth from regulators, auditors that tried to check on the investment business, said Zach.

"When he was asked about it, he lied about it," the prosecutor argued.

Bonventre received nearly $15 million during his Madoff tenure, using the money to fund vacations, pay private-school tuition for his son and other personal expenses, said Zach. He argued that that the former manager lied about his role in the scam when he took the witness stand in his own defense.

Bongiorno, the only other defendant who testified, told jurors she revered Madoff and carried out his instructions without knowing the tasks he assigned her could be illegal. But Zach termed Bongiorno's testimony "not credible."

Prosecution evidence showed she helped craft years of phony trading records and falsify documents sought by auditors and regulators, argued Zach, who noted Bongiorno collected more than $18 million that helped pay for posh New York and Florida homes and a Bentley luxury auto.

Crupi had a key role in crafting falsified trading records that fooled Securities and Exchange Commission regulators and auditing firms, argued Zach. Prosecution evidence also showed she directed that fake trades be placed in her own investment account and tried to get one final payout as the scam imploded, he said.

Perez and O'Hara wrote dozens of computer programs that enabled Madoff to falsify investor statements, backdate trades and produce radically different sets of records presented to auditors and regulators, said Zach.

"They essentially were the oil that made the fraud work," the prosecutor said of the computer programs.

When the programmers said they were uncomfortable about continuing, Zach said evidence showed they sought more money - once seeking payment in diamonds - but stayed in their jobs.